Individual-call instrument for telephones



(No Model.)

2 sheets- -sheef; 1.

J. P. STABLER. V INDIVIDUAL CALL INSTRUMENT FOR TELEPHONES. No, 306,361.

Patented Oct. 7, 1884.

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(No Model.) 2 Sheets-Sheet 2. J. P. STABLER.

INDIVIDUAL GALL INSTRUMENT FOR TE LEPHONES. No. 306,361. Patented001197, 1884.

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JAMES P. STABLER, OF SANDY SPRING, MARYLAND.

lNDlVlDUAL-CALL QNSTRUIVIENT FOR TELEPHONES SPECIFICATION forming partof Letters Patent No. 306,361, dated October 7, 1884. Application filedJanuary 26, 1884. (No model.)

To aZZ whom it may concern.-

Be it known that I, J AM ES PLEASANTS STA- BLER, of Sandy Spring,Montgomery county, in the State of Maryland, have invented new anduseful Improvements in Individual-Gall Apparatus for Telephone-Lines andI do hereby declare that the following is a full and accuratedescription of the same.

This improvement relates more particularly to the invention for whichLetters Patent No. 265,454 were granted to me October 3, A. D. 1882; andit consists in the improvement in the push-and-pull pawl, in theescapement or detent for the ratchet-wheel actuated by said pawl in theelectrical connections in the box, in the single-current commutator onthe axis of the generator, whereby the current which drops theannunciator at the exchange is always in the same direction as theoffice-bell current of the central-office instrument, and

in the mode of holding magnets on the frame.

The general structure and operation of the instrument shown herein beingfully described in my said patent, and now well known, it will only benecessary herein to describe in detail those portions which form thesubject of the present improvement.

Figure l is a perspective View, my call-box open, the electricalconnecting-wires being omitted. Fig. 2 is a plan of the same with allthe electrical connections. Fig. 3 is a perspective view of thearmature-pinion and single-current cOntactspring.

For convenience I will describe the parts improved in the order namedabove. In my said patent the msh-andpull pawls to actuate the ratchet Sand index L are constituted of two arms coincidently .jointcd to the endof the arm G, carried by the armature B, and drawn together by a spring,the ends of which are attached to the pawls, respectively. This mode ofconstruction requires the making and handling of five separate pieces,and considerable labor, 8:0. I now dispense with the separate pivotedarms and substitute a pair of pawls made from a single strip or ribbonof steel, as at D, bent at the middle to form an eye, b, capable ofembracing the body of the screw 0, or, preferably, the perforatedbushing I), to which the eye 6 may be fastened by solder or otherwise,if required. The screw 0 then passes through the perforation in thebushing, and thereby pivots the pawls upon the arm 0. The end f isfinished plain to push upon the teeth of the ratchet, while the end g isturned around inward to form a hook and pull upon the teeth of theratchet. The elasticity of the ribbon D affords all the attentionrequired to keep both pawls in their duty. In my said patent I havedescribed the necessity of an escapement to positively arrest theratchet and index switch when the pawl movement ceases. The ratchet,&c., shown in the patent has reference to the 10- cal-station instrumentwherein in each instrument there are but two points where such arrest isrequired; but in the central-office instrument the same arrest isrequired for each pawl movement; otherwise the indexswitch of thecentral-ofiice instrument may by momentum move too far and make contactwith the key-stops too soon, thus cutting out the line before the localswitch has reached its bell-shunt. Under these circumstances the properhell would not be rung; but at the central oflice there would not be anyindication of that fact. It was contemplated to employ with the centraloffice a ratehet-wheel having an escapement pin for each local stationon the line, so that my escapement would arrest at each movement. Thisinvolves a great deal of trouble in adjustment, and I have substitutedfor the cscapement arms and pins a pair of rigid arms l?) E, carried bythe arm 0, and having their ends located near the edges of the ratchetin close proximity thereto on opposite sides and about midway betweenthe points of contact of the pawls measuring around the circumference ofthe ratchet-wheel. These arms vibrate with the arm C and upon the samecenter. At the close of each reeiprocation of the pawls and advance ofthe ratchet one or the other of said arms E is in close contiguity tothe inclined face of the ratchettooth and ready to arrest th same ifmomcn- 9 tum shall cause any continuance of motion. Thus a perfectescapement arrestprovided without any of the delicate adjustmentsrequired where a series of pins shall be used, because theratchet-teeth. are closely dupli- 5 out is to ground, and the line in iscates, and when the arms E are ad j nsted to one pair of said teeth theadjustment will be sufficient for all. g

The change in electrical connection from that shown in Patent No.265,454 may be indicated as follows: In said patent, when the index ison the bell-shunt and thelever down, the current is through said shunt,but does not enter the lever at all. It goes to a switchspringcontrolled by said lever, and on one side said spring makes connectionwith the telephone and line, and on the other side it makes connectionwith the belland line, and one or theother of these connections is madeaccording as the lever is up or down. In the present improvement Idispense with the side con tacts and arrange the switch-spring to breakcontact with the lever when down and make contact therewith when it isup, and connect the bell on one side with said spring and on the otherwith the lever, whereby when the lever is down the bell will be incircuit,

and when the lever is up the bell will be cut from the central office.For convenience also, the electrical connections will be separatelytraced under the several conditions in which they may be 'in the use ofthe instrument. lVhen the station is called by the operator at thecentral office, the telephone being on the hooks at the station. \V henthe index-switch Lis traveling to the local shuntof the station (S) tobe called, supposing it starts from the unison shunt Z, the current willfirst pass over the following line, to wit: line in post h, tomotor-magnets A A, to indexswitch L, to detent-shunt Z, to detent Q,detent-magnets R, wire 1, to hook lever j, to spring 70, wire 2, tobutton Z by spring on, to frame of station-generator V, wire 3, tolineout post a. When the index-switch L passes from the detent-shunt Ztothe dial-rim a, thecurrent goes by way of said rim and wire 24: to theline-out post a direct. XVhcn theindexswitch L passes on to the localstation or beltshunt s, the current then passes by means of said shuntand wire 7' to hinge t, wire 8, to bell-magnet T, wire 9, to hinge u,and to hooklever j, to contact-spring k, wire 2, to button Z, by pushbutton spring m, to frame of local generator V and wire 3, to line outpost 42. The bell-magnet T, then being in circuit, the bell is caused toring bya current of adequate strength. The call being heard, thetelephone is taken down and, the circuit will then be as follows: PostIt to motor-magnets A A, to indeX-switch L, to stationshunt s,wire 7, tocontact-spring 00, along lever j, to spring (1 by wire 4, to thesecondary coil XV of the transmitter by wire 5, to post 1, wire 6, totelephonewire 2, to button Z, spring m, frame of generator V, and wire3, to line out post it. This circuit remains until the communication orconversation is terminated, when the central office is notified of thatfact by ringing off, the telephone being first replaced upon the hookand the push-button 0 being pushed in to break contact with the buttonZ. of the local generator V being normally in connection with the outpostn, ,a pin, 2, on the armaturepinion 1) makes cont-act at eachrevolution with the spring 2, which is in connection by wire 23 with thebutton I, and thence by way of contact spring 1) with the oppositeterminal of the armature-coil, so that during each revolution of thearmature one current will be shortcircuited through the generator by wayof pin .2, button Z, and spring 1), and the other current will go to theline. The pin a is so located that the current which goes to the linewill be in the same direction as the re-enforce current from the centraloffice. While ringing off, the currents to the line will be, generatorframe V to out post 02, and from spring 1) by wire 2 to contact-spring7G, to lever j by wire 9, to hinge a, and to bellmagnets T, wire 8, tohinge 7., wire 7, to local shunts, index-switch L, motor-magnets A A,post h, line to central oflice.

IVhen it is desired to call up the central oflice, the telephone is uponthe hook, and the switch upon the detent or unison shunt z. Thepush-button 0 is pushed in to break contact with button Z. WVhen thecrank is turned, the current will then be, generator-frame to out posta, and from springs 19 by wire 2 to contact-spring 7c, lever j, and wire1, to detentmagnet It, index-switch L, motor-magnets A A, and post h, toline. Vhen call is answered, take the telephone from the hook and thecurrents will be, generator-frame by wire 3, to post a and spring 1),and wire 2 to telephone-wires (3 and 5, to secondary coil of thetransmitter-wire 4, to contact-spring q, lever j, wire 1, detent-magnetsR, indexswitch L, motor-magnets A A, and post h to line. This completesthe several connections under the various conditions of use. The primarycoil U of the inductorium is in the short local circuit of the batteryX, as is usual.

Ithas been found necessary to fix the motor-magnets very firmly inposition with refi erence to the polarized armature, so as to secure theexact movement of the latter necessary to operate the push-and-pull pawland ratchet of the index-switch. I therefore provide the three-ar1nedclamp-plate Z, two arms of which engage the spool ends, and'the otherengagestheyokey. Ascrew,s,passesthrough said clamp, between the magnetsand into the frame G, so as to bind the spools firmly against saidframe, which is also provided with seats prepared to receive and engagethe spool ends.

As an additional precaution against the shifting of themagnets fromrough handling, shipment, or other accidental concussion, a pin, 0, ispassed through a hole in the frame into the spool end.

The frame Having described my invention, I claim- 1. The push-and-pullpawl made from a single strip or ribbon of spring tempered steel orequivalent meta], bent at its middle to form an eye, I), and the ends fg, finished as described, and for the purpose set forth.

2. The push-and-pull pawl made from a single strip or ribbon, l), ofspring tempered steel or equivalent metal, bent at its middle to form aneye, I), combined with the perforated bushing 1), permanently fastenedtherein, the arm 0 of the vibrating armature B, and the ratchet S of theindex-switeh L.

3. The push-and-pull pawl l), the revolving ratchet S, and vibrating arm0, whereby said pawl is actuated, combined with the escapeinent-arms 10E, permanently attached to and carried by said arm 0, and adjusted toapproach and stop close to but not in engagement with the edge of theratchet, as and for the purpose set forth.

4. A rotating ratchet, S, and yibrating arm 0, combined with apush-and-pull pawl, D, both attached tosaid arm at the same distancefrom its center of motion, and escapementarms E E, both pawl andescapeinent being carried by said arm, but arranged to approachand-engage the edge of the ratchet from directions respectivelyperpendicular to each other.

5. A rotating ratchet and avibrating arm, 0,

combined with escapeinent-arms E E, rigidly attached to and vibratingwith said arm upon its center of motion, and an elastic push-andpullpawl, D, carried by said arm and pivoted thereto at a point ninetydegrees with reference to the axis of the ratchet from theescapement-arins axis of motion.

6. In an individual call-instrument for telephone-lines, the telephonehook-lever j, con tact-springs x q, and their electrical connections, incombination with the contact-spring 7., whereby when said lever is downcontact is made with said lever, and the currents shortcircuited to cutout the transmitter and telephone, as described.

7. The spring z, arranged to make singlecurrent contacts with the pin aon the revolving spindle of the armature, for convenience, say, on oneside of the generator, and placed in electrical connection with thearmature on the other side of the generator, whereby the alternatecurrents are short-circuited through the generator and currents in thesame direction as central-office bell-current are 'sent to the lineonly.

JAMES P. STABLER.

Vi tnesses:

R. D. 0. SMITH, J. O. TURNER.

